The present invention generally relates to fabrication methods and resulting structures for semiconductor devices. More specifically, the present invention relates to fabrication methods and resulting structures for FinFET transistors, wherein contacts of the FinFET are made from low-resistance metals.
The metal oxide semiconductor field effect transistor (MOSFET) is a transistor used for switching electronic signals. The MOSFET has a source, a drain, and a metal oxide gate electrode. The metal gate is electrically insulated from the main semiconductor n-channel or p-channel by a thin layer of insulating material, for example, silicon dioxide or high dielectric constant (high-k) dielectrics, which makes the input resistance of the MOSFET relatively high. The gate voltage controls whether the path from drain to source is an open circuit (“off”) or a resistive path (“on”).
A FinFET is a non-planar MOSFET structure that has as a main feature an elongated fin-shaped element. The gate is wrapped around a central portion of the fin. The portion of the fin that is under the gate functions as the channel. The portions of the fin that are not under the gate function as the source or the drain (S/D), respectively. The thickness of the fin determines an effective channel length of the device.